1. Field of the Invention
The present invention generally relates to a touch device, light source module, and a light source structure thereof, and more particularly, to a touch device, light source module, and a light source structure having a laser light source.
2. Description of Related Art
Conventional touching panels include different types of touching panels, such as a resistance type touching panel or a capacitance type touching panel. Wherein the touching panels mentioned above are operated by measuring the resistance variance or the capacitance variance for defining the touching position for performing an input process while an input medium, for example, the human body or a touching pen, touching the touching panel.
Because the touching panels mentioned above are made of a plurality of films, the visual effect of the display screen having a touching panel is influenced by the transparent properties of the films directly. The visual effect of the display screen is also influenced by the properties of color distortion, reflective properties, and definition. If any one of the properties mentioned above is not proper, the visual effect of the display screen would become poor. Besides, while performing an input process, an input medium, a finger or a touching pen must touch the touching panel mentioned above. In order to achieving a proper input result, it is necessary to touch the touching panel with a certain degree of pressure. It is easy to scratch the surface of the touching panel. Moreover, the resolution of the conventional touching panel is limited by the circuit lay out of the touching panel. Thus, the touching panels mentioned above are not suitable for a large-size touching panel having high resolution.
Conventional touching panels also include the optical type touching panel wherein the optical method is used to be a medium for detecting the touching position. The advantage of the optical type touching panel is that the visual effect of the display screen is not be influenced. The resolution of the optical type touching panel is defined by the density of the optical sensors and the resolutions of firmware and software.
Generally speaking, there are two methods for applying laser as the medium of detecting the touching position. The first method is using laser arrays, wherein each laser unit is corresponding to one laser detecting sensor. As the resolution of the optical type touching panel is increased, the number of the laser unit and laser detecting sensor is also increased. Accordingly, the manufacturing cost, energy consumption, and heat generated are also increased. That is not good for the realization of the product. The LED array can improve the disadvantages mentioned above. However, the LED light source is a divergent light source, and the laser light source is a coherent light source. Hence, when using the LED array as medium for detecting the touching position, it is only possible to achieve the effect of analog signals, not the digital signals. There is also a method using a single laser source and a scanning mechanism which includes an oscillator or a rotating motor for achieving the purpose of scanning a detecting surface. The advantage of this method is low manufacturing cost. However, both the oscillator and the rotating motor will generate electromagnetic wave; the communicating quality of the original product may be interfered with the electromagnetic wave. Moreover, there is also a method which uses a single laser source and a beam-splitter mirror array. The energies of the laser beams projected from the beam-splitter mirror array are distributed unequally. As the number of mirror is increased, the energies of the laser beams projected from the beam-splitter mirror array are decayed quickly. Thus, it is difficult or impossible to detect all of the laser beams projected from the beam-splitter mirror array. In other words, realization value of this method is poor.
Moreover, as disclosed in U.S. Pat. Nos. 7,242,388, 7,305,368, 7,417,681, and 6614422, a specific pattern is projected to a detecting plane as a reference pattern for detecting the touching position. The imagines of the detecting plane are compared for defining the touching position. Because comparing the images is performed by analog signals, it is necessary to use a signal processor for performing the complicated analog calculation so as to define the touching position. Therefore, this method is not suitable for a touch device having high resolution or high response speed.